Compact direct drive spindle

ABSTRACT

A sealed actuator including stacked motor modules. Each motor module has a motor module housing, a motor stator attached to a respective motor module housing, a motor rotor in communication with a respective motor stator, and a stator seal disposed between the motor stator and motor rotor, surrounding the motor rotor and having a sealing surface interface, that interfaces with a respective sealing housing surface of the motor module housing, facing the motor rotor to seal the motor stator from the motor rotor. The motor module housings are stacked against each other and the sealing housing surface interfaced, at the sealing surface interface facing the rotors, to the respective stacked stator seals of the motor module housings forms a substantially continuous seal interface of the stacked motor modules sealed by the stacked stator seals to form a continuous barrier seal between the motor rotors and the motor stators.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Non-provisional patentapplication Ser. No. 17/468,181 filed Sep. 7, 2021, which is adivisional of U.S. Non-provisional patent application Ser. No.16/702,403, filed Dec. 3, 2019, which is a continuation ofNon-provisional patent application Ser. No. 15/695,744, filed on Sep. 5,2017, (now U.S. Pat. No. 11,110,598), which is a continuation of U.S.Non-provisional patent application Ser. No. 14/941,888, filed on Nov.16, 2015 (now U.S. Pat. No. 9,751,209), which is a continuation of U.S.Non-provisional patent application Ser. No. 13/547,786 filed on Jul. 12,2012 (now U.S. Pat. No. 9,186,799) which claims the benefit of andpriority from U.S. Provisional Patent Application No. 61/510,819 filedon Jul. 22, 2011 and U.S. Provisional Patent Application No. 61/507,276,filed on Jul. 13, 2011, the disclosures of which are incorporated hereinby reference in their entireties.

BACKGROUND 1. Field

The exemplary embodiment generally relates to drives for robot systems,and more particularly, to spindle drives for robot systems.

2. Brief Description of Related Developments

Current vacuum robots either use a ferrofluidic or lip seal to isolatethe motors and encoders from vacuum, or in the case of the BrooksMAGNATRAN® products, isolate the motor stators using a barrier wall butplace the magnet rotor and encoders directly in the vacuum environment.In both of these cases, the motor is placed below the bellows and shaftsare used to connect the motor to the robot arm links.

It would be advantageous to leverage an inverted drive design thatplaces the stators on a stationary inner post and the rotor to theoutside of the stators.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and other features of the disclosed embodimentsare explained in the following description, taken in connection with theaccompanying drawings, wherein:

FIG. 1 is a schematic illustration of a portion of a substrateprocessing apparatus incorporating features in accordance with aspectsof the disclosed embodiment;

FIG. 2 is a schematic illustration of a portion of a substrateprocessing apparatus incorporating features in accordance with aspectsof the disclosed embodiment;

FIG. 3 is a schematic illustration of a substrate transport apparatus inaccordance with aspects of the disclosed embodiment;

FIGS. 4A-4D are a schematic cross-sectional views of a robot drivesystem in accordance with aspects of disclosed embodiment;

FIG. 5A is a schematic cross-sectional view of a portion of a transferapparatus in accordance with aspects of the disclosed embodiment;

FIG. 5B is a schematic cross-sectional view of a portion of the transferapparatus Of FIG. 5A in accordance with aspects of the disclosedembodiment;

FIG. 6 is a schematic cross-sectional view of a portion of a transferapparatus in accordance with aspects of the disclosed embodiment;

FIG. 7 is a schematic cross-sectional view of a portion of a transferapparatus in accordance with aspects of the disclosed embodiment;

FIG. 8 is a schematic cross-sectional view of a portion of a transferapparatus in accordance with aspects of the disclosed embodiment;

FIG. 9 is a schematic cross-sectional view of a portion of a transferapparatus in accordance with aspects of the disclosed embodiment;

FIG. 10 illustrates a portion of an exemplary sensor system inaccordance with aspects of the disclosed embodiment; and

FIG. 11 illustrates an exemplary arrangement of magnetic sensors arounda ferromagnetic element in accordance with aspects of the disclosedembodiment.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT(s)

FIG. 1 is a schematic illustration of a substrate processing apparatusincorporating features in accordance with aspects of the disclosedembodiment. Although the aspects of the disclosed embodiment will bedescribed with reference to the drawings, it should be understood thatthe aspects of the disclosed embodiment can be embodied in manyalternate forms. In addition, any suitable size, shape or type ofelements or materials could be used. Further, although the aspects ofthe disclosed embodiment will be described in the context of a vacuumrobot it should be noted that the aspects of the disclosed embodimentencompasses any situation where a drive motor may be used.

The substrate processing apparatus 100 shown in FIG. 1 is arepresentative substrate processing tool incorporating features inaccordance with aspects of the disclosed embodiment. In this example theprocessing apparatus 100 is shown as having a general batch processingtool configuration. In other aspects the tool may have any desiredarrangement, for example the tool may be configured to perform singlestep processing of substrates or have a linear or Cartesian arrangementsuch as shown in FIG. 2 . In still other aspects, the substrateprocessing apparatus may be of any desired type such as sorter, stocker,metrology tool, etc. The substrates S processed in the apparatus 100 maybe any suitable substrates including, but not limited to, liquid crystaldisplay panels, solar panels, semiconductor wafers, such as a 200 mm,300 mm, 450 mm diameter wafers, or any other desired diameter substrate,any other type of substrate having any suitable shape, size andthickness suitable for processing by substrate processing apparatus 100,such as a blank substrate, or an article having characteristics similarto a substrate, such as certain dimensions or a particular mass.

In one aspect, the apparatus 100 may generally have a front section 105,for example forming a mini-environment and an adjoining atmosphericallyisolatable or sealed section 110 that can be sealed from an externalenvironment for holding a controlled sealed atmosphere, which forexample may be equipped to function as a vacuum chamber. In otheraspects, the sealed atmosphere section may hold an inert gas (e.g. N₂)or any other environmentally sealed and/or controlled atmosphere.

The front section 105 may generally have, for example one or moresubstrate holding cassettes 115, 115 a, 115 b, and a front end robot120. The front section 105 may also, for example, have other stations orsections such as an aligner 162 or buffer located therein. Section 110may have one or more processing modules 125, 125 a-125 f, and a vacuumrobot arm 130. The processing modules 125, 125 a-125 f may be of anytype such as material deposition, etching, baking, polishing, ionimplantation cleaning, etc. As may be realized the position of eachmodule, with respect to a desired reference frame, such as the robotreference frame, may be registered with controller 170. Also, one ormore of the modules may process the substrate(s) S with the substrate ina desired orientation, established for example using a fiducial (notshown) on the substrate. Desired orientation for substrate(s) inprocessing modules may also be registered in the controller 170. Sealedsection 110 may also have one or more intermediate chambers, referred toas load locks. The apparatus 100 shown in FIG. 1 has two load locks,load lock 135 and load lock 140. Load locks 135, 140 operate asinterfaces, allowing substrates S to pass between front section 105 andsealed section 110 without violating the integrity of anyenvironmentally sealed atmosphere that may be present in sealed section110. Substrate processing apparatus 100 generally includes a controller170 that controls the operation of substrate processing apparatus 100.In one embodiment the controller may be part of a clustered controlarchitecture as described in U.S. patent application Ser. No.11/178,615, filed on Jul. 11, 2005, the disclosure of which isincorporated by reference herein in its entirety. The controller 170 hasa processor 173 and a memory 178. In addition to the information notedabove, memory 178 may include programs including techniques foron-the-fly substrate eccentricity and misalignment detection andcorrection. Memory 178 may further include processing parameters, suchas temperature and/or pressure of processing modules, and other portionsor stations of sections 105, 110 of the apparatus, temporal informationof the substrate(s) S being processed and metric information for thesubstrates, and programs, such as algorithms, for applying thisephemeris data of apparatus and substrates to determine on the flysubstrate eccentricity.

The front end robot 120, also referred to as an ATM (atmospheric) robot,may include a drive section 150 and one or more arms 155. At least onearm 155 may be mounted onto drive section 150. The at least one arm 155may be coupled to a wrist 160, which in turn is coupled to one or moreend effector(s) 165 for holding one or more substrate(s) S. Endeffector(s) 165 may be rotatably coupled to wrist 160. ATM robot 120 maybe adapted to transport substrates to any location within front section105. For example, ATM robot 120 may transport substrates among substrateholding cassettes 115, 115 a, 115 b, load lock 135, and load lock 140.ATM robot 120 may also transport substrates S to and from the aligner162. Drive section 150 may receive commands from controller 170 and, inresponse, direct radial, circumferential, elevational, compound, andother motions of ATM robot 120.

The vacuum robot arm 130 may be mounted in central chamber 175 ofsection 110. Controller 170 may operate to cycle openings 180, 185 andcoordinate the operation of vacuum robot arm 130 for transportingsubstrates among processing modules 125, 125 a-125 f, load lock 135, andload lock 140. Vacuum robot arm 130 may include a drive section 190 (aswill be described in greater detail below) and one or more end effectors195. In other aspects, ATM robot 120 and vacuum robot arm 130 may be anysuitable type of transport apparatus, including but not limited to, asliding arm robot, a SCARA (selectively compliant articulated robot arm)type robot, an articulating arm robot, a frog leg type apparatus, or abi-symmetric transport apparatus.

Referring to FIG. 2 , there is shown a schematic plan view of anothersubstrate processing apparatus 10 incorporating features in accordancewith aspects of the disclosed embodiment. The substrate processingapparatus 10 is illustrated as having a linear or Cartesian arrangementin which substrates S are passed between transfer robots through anelongated transfer chamber. The substrate processing system 10, or tool,generally has a processing section 13 and an interface section 12. Theinterface and processing sections of the tool 10 are connected to eachother and allow transport of workpieces there between. The processingsection 13 of the tool may have processing modules or chambers,substantially similar to those described above with respect to FIG. 1 .The processing modules may be linked by a workpiece transport chamber 16in which the workpieces may be transported between desired processingmodules according to the processing protocol. The transport chamber hasa transport robot 20 capable of moving the workpieces therein and to theprocessing modules 125, 125 a-125 f. The processing modules 125, 125a-125 f and the transport chamber are capable of being atmosphericallyisolated so they are able to hold a controlled atmosphere that isenvironmentally sealed from an exterior atmosphere in order to maintainatmosphere within the transport chamber the same as the processingmodules, or suitable for workpieces being transferred between processingmodules in a manner substantially similar to that described above withrespect to FIG. 1 . The tool interface section 12 provides a workpieceloading/unloading interface between the tool processing section 13 andits controlled sealed atmosphere and the tool exterior. An example of asuitable environmental interface section is disclosed in U.S. patentapplication Ser. No. 11/178,836, filed Jul. 11, 2005 incorporated byreference herein in its entirety. The tool interface section thus allowsworkpieces, that may be transported in carriers outside the tool, to beunloaded from the carrier into the tool and vice versa. The transportchamber may be made up of transport chamber modules, that may beconnected end to end for example to form a linearly elongated transportchamber. The transport chamber length is thus variable by adding orremoving transport chamber modules. The transport chamber modules mayhave entry/exit gate valves capable of isolating desired transportchamber module from adjoining portions of the transport chambers. Toolinterface sections similar to section 12 may be positioned at anydesired locations along the linearly elongated transport chamberallowing workpieces to be loaded or unloaded at a desired location inthe tool. Processing modules may be distributed along the length of thetransport chamber. The processing modules may be stacked in a directionangled to the length of the chamber. The transport chamber modules mayhave entry/exit gate valves to isolate desired transport chamber modulesfrom the processing modules. The transport system 20 is distributedthrough the transport chamber. A number of the transport chamber modulesmay each have an integral movable arm having a fixed interface/mount tothe module and movable end effector capable of holding and movingworkpieces linearly along the transport chamber and between transportchamber and processing modules. Transport arms in different transportchamber modules may cooperate to form at least a portion of the linearlydistributed transport system. Operation of the transport system,processing modules, processing section, interface section and any otherportions of the tool may be controlled by controller 400 that may besubstantially similar to controller 170 described above. The transportchamber and transport system therein may be arranged to define multipleworkpiece travel lanes within the transport chamber. The travel lanesmay be polarized or dedicated within the transport chamber for advanceand return of workpieces. The transport chamber may also haveintermediate load locks allowing different sections of the transportchamber to hold different atmospheres, and allow workpieces to transitbetween the different atmospheric sections of the transport chamber. Thetransport chamber may have an entry/exit station(s), where workpiecesmay be inserted/removed from a desired location of the transportchamber. For example, the entry/exit station may be located at anopposite end from the interface section 12 or other desired position inthe transport chamber. The entry exit station(s) of the transportchamber may communicate with a workpiece express transit passage linkingentry/exit station of the transport chamber with a remote tool interfacesection 12. The express transit passage may be independent of andisolatable from the transport chamber 16. The express transit passagemay communicate with one or more of the interface section 12 so thatworkpieces may be transported between the interface section and transitpassage. Workpieces may be rapidly placed into an advanced section ofthe tool and returned to the interface section 12 after processing viathe express transit passage without affecting the transport chamber, andresulting in a reduction of work in process (WIP). The transport chambermay also have intermediate entry/exit stations, a number of which maycommunicate with the express transit passage so that workpieces may betransported there between. This allows workpieces to be inserted orremoved at desired intermediate portions of the process withoutaffecting the process stream as described in U.S. patent applicationSer. No. 11/442,511 filed on May 26, 2006, the disclosure of which isincorporated herein by reference in its entirety.

The interface section 12 mates directly to the transport chamber (asshown in FIG. 1 ) without any intervening load locks. In other aspects aload lock may be placed between the interface section 12 and thetransport chamber. The interface section shown in FIG. 2 has a workpiecetransport 15 for moving workpieces from a cassette 115 mated to the loadport LP, to the transport chamber 16. The transport 15 is located insidethe interface section chamber 14, and may be substantially similar tothe transport 150 described above. The interface section may alsoinclude workpiece station(s) A such as an aligner station, bufferstation, metrology station and any other desired handling station forworkpiece(s) S.

Although some aspects of the disclosed embodiment will be describedherein with respect to a vacuum robot or transport, such as for exampletransport 800 of FIG. 3 , it should be realized that the disclosedembodiment can be employed in any suitable transport or other processingequipment (e.g. aligners, etc.) operating in any suitable environmentincluding, but not limited to, atmospheric environments, controlledatmosphere environments and/or vacuum environments. In one aspect, thetransport 800 may have for example multiple independently movable endeffectors for independently moving multiple workpieces. The transport800 shown in FIG. 3 is illustrated for example as a multi-articulatedlink arm, that may have any suitable numbers of degrees of freedom infor example rotation, extension/retraction and/or lift (e.g. Z-axismotion). It should also be realized that the transports incorporatingaspects of the exemplary embodiments can have any suitable configurationincluding, but not limited to, sliding arm robot configuration, the“frog leg” configuration of robot arm, the SCARA arm configuration ofrobot, an articulating arm robot or a bi-symmetric transport apparatus.Suitable examples of robot arms with which the drive system of theexemplary embodiments may be employed can be found in U.S. Pat. Nos.4,666,366; 4,730,976; 4,909,701; 5,431,529; 5,577,879; 5,720,590;5,899,658; 5,180,276; 5,647,724 and U.S. application Ser. No. 11/148,871filed on Jun. 9, 2005; Ser. No. 12/117,415 filed on May 8, 2008; Ser.No. 11/697,390 filed on Apr. 6, 2007; Ser. No. 11/179,762 filed on Jul.11, 2005; Ser. No. 13/293,717 filed on Nov. 10, 2011; and Ser. No.13/417,837 filed on Mar. 12, 2012 the disclosures of which areincorporated herein by reference in their entireties.

Referring now to FIGS. 3 and 4A-4D, the exemplary transport apparatus800 incorporating aspects of the disclosed embodiments will be describedin greater detail in accordance with aspects of the disclosedembodiment. It is noted that while single SCARA arm is shown in FIGS. 3and 4A-4D the aspects of the disclosed embodiments can be incorporatedinto any suitable type of robot arm such as those described above havingany suitable number of robot arms. In this aspect the transportapparatus includes a frame 840, an upper arm 810, a forearm 820 and atleast one end effector 830. A drive section 1600 may be located at leastpartially within the upper arm 810 and include at least one drive motor1602A, 1602B. Here two motors 1602A, 1602B are shown for exemplarypurposes as being stacked drive motors that are disposed, so that atleast part of the stator 1603A, 1603B for each drive motor 1602A, 1602Bis located in the arm link 810 (e.g. at least part of the stator foreach drive motor is located in the same arm link, or a common arm link,or a single arm link, or one arm link). Each of the at least one drivemotor 1602A, 1602B may include a stator 1603A, 1603B and a rotor 1604A,1604B. The stators 1603A, 1603B may include stator windings that arewrapped around a stationary post 1610 that is fixed to the frame so thatthe post 1610 and the stator(s) 1603A, 1603B remain rotationallystationary relative to movement of the robot arm links 810, 820, 830.The rotors 1604A, 1604B may be configured such that the rotors surroundthe respective stators (e.g. inverted drive motors) to form a shaftlessmotor(s) that may provide a compact design and higher torque thanconventional shaft drives. It is noted that the term “shaftless” denotesthat there is substantially no extension portion or member between therotor and the member driven by the rotor, where a height of the rotor issubstantially coincident with or less than a height of the stator (e.g.height of the stator windings). By way of further example, an engagementinterface between the rotor and the member driven by the rotor isproximate the stator. The stators and rotors may include characteristicssuch as those described in U.S. Pat. No. 7,834,618 and U.S. patentapplication Ser. No. 12/163,993 filed on Jun. 27, 2008 and Ser. No.12/163,996 filed on Jun. 27, 2008 the disclosures of which areincorporated by reference herein in their entireties. Further, as willbe described in greater detail below, encoders or other suitable sensorsfor determining rotatory position of the shaftless motors may bepositioned within the profile space or dimension (e.g. height) of thestator so as to be included within the height of the shaftless motor ormotor stack.

In this aspect the two drive motors 1602A, 1602B are stacked one abovethe other. The drive motors 1602A, 1602B may be stackable to allow foreasy adoption of multiple motors for providing any suitable number ofdegrees of freedom for driving any suitable number of arm links. Inother aspects, any suitable number of drive motors (i.e. at least one ormore) may be used in any suitable configuration having any number ofsuitable drives, such as, but not limited to, a stacked inverted driveconfiguration, an in-line inverted drive configuration, or any othersuitable configuration. Here the rotor 1604A of drive motor 1603A isshaftlessly coupled to the arm link 810 so that as the rotor 1604Arotates the arm link 810 rotates with it. For example, the rotor 1604Amay be mounted in any suitable manner to a lower surface of the arm link810. The rotor 1604B of motor 1603B may include (either integrallyformed with or coupled to) a pulley 1605. The pulley may be coupled toan elbow pulley 1620 through any suitable transmission member 1605X. Inone aspect, the transmission member 1605X may be a belt, band, wire orany other suitable transmission member. The elbow pulley 1620 may besuitably connected to the forearm 820 in any suitable manner such thatas the rotor 1604B rotates it causes the forearm 820 to rotate about anelbow axis of rotation EX.

Referring also to FIGS. 10 and 11 , the inverted drives 1602A, 1602B mayinclude any suitable sensors for tracking the rotation of the rotors1604A, 1604B. In one aspect, any suitable encoders 1640A, 1640B may beprovided at suitable locations for sensing the rotation of a respectiveone of the rotors 1604A, 1604B. In one aspect the encoders 1640A, 1604Bmay interface directly with a respective rotor 1604A, 1604B (e.g. thesensor scale is integrated into the rotor) where the encoders 1640A,1640B are stationarily located on or depend from the fixed post 1610such that the interface plane between the sensor system 5500 and scale(or ferromagnetic target) 5555 of the encoder is arranged, for example,at an angle relative to the interface plane between the stator 1603A,1603B and the rotor 1604A, 1604B so that the sensor system 5500 may bedisposed substantially within a height of the stator 1603A, 1603B. Forexemplary purposes only, the interface plane IPSS between the sensorsystem 1500 and the ferromagnetic target 5555 is shown as beingsubstantially orthogonal to the interface plane IPSR between the stator1603A, 1603B and the rotor 1604A, 1604B. The rotors 1604A, 1604B caninclude any suitable scales or ferromagnetic targets 5555 such asincremental scales 1640IN (FIG. 4C) or absolute scales 1640AB (FIG. 4C)which the sensor system 5500 of the encoders 1640A, 1640B detect forposition measurement. It is noted that any suitable seal(s) 1640S (FIG.4C) may be provided for sealing or otherwise isolating the encoders1640A, 1640B from, for example, the environment (e.g. vacuum environmentor otherwise) in which the transport apparatus arms operate. Forexample, seals 1640S may be disposed between the encoders 1640A, 1640Band their respective rotors. The seals 1640S may be configured such thatthe encoders 1640A, 1640B are capable of reading or otherwisesensing/detecting the scales or ferromagnetic targets 5555 such asincremental scales 1640IN (FIG. 4C) or absolute scales 1640AB (FIG. 4C).

FIG. 10 shows an exemplary sensor system 5500 suitable for use with theaspects of the disclosed embodiment described herein. Sensor system 5500may utilize any suitable magnetic circuit principles, for example, suchas those described in U.S. Pat. No. 7,834,618 (the disclosure of whichis incorporated herein in its entirety) to read incremental orabsolutely position scales and/or a distance from the ferromagnetictarget 5555 to, for example, the sensor system's reference frame. Theferromagnetic target 5555 may be a flat or curved surface or have anysuitable profile attached to, embedded in, or otherwise integral to thetarget such as, for example, the scales discussed above. The sensorsystem 5500 may include a ferromagnetic element 5505, a magnetic source5510, for example, a permanent magnet, a number of magnetic sensors5515, 5520, 5525, 5530 and conditioning circuitry 5535. Theferromagnetic element 5505 may circumscribe the magnetic source 5510. Inother aspects, the ferromagnetic element 5505 may surround or evenenclose the magnetic source 5510. In at least one exemplary embodiment,the ferromagnetic element 5505 may have a cup shape with a closed end5565 and an open end 5570. The magnetic source 5510 may have acylindrical shape where the direction of magnetization is parallel tothe axis of symmetry of the ferromagnetic element 5505. The magneticsource 5510 may be a permanent magnet, an electromagnet, or any othersuitable source of magnetic energy. The magnetic source 5510 may beattached within the ferromagnetic element to the center of theferromagnetic element 5505 by attractive forces and may be held in placeusing a suitable fastener, for example an adhesive. In one aspect, thesensor system 5500 may be oriented such that the open face 5570 of thecup faces the ferromagnetic target 5555.

The sensor system 1500 illustrated in FIG. 10 may establish a magneticcircuit between the ferromagnetic element 5505 and the magnetic source5510 such that the flux density is symmetric about the axis of the cupor any concentric perimeter between the magnetic source 5510 and theferromagnetic element 5505. The shape of the ferromagnetic element 5505influences the shape of the magnetic field. In aspects where theferromagnetic element 1505 is cup shaped, the magnetic field isrelatively confined, resulting in an increased sensitivity to variationsin the distance 5560 to the ferromagnetic target. The ferromagneticelement 5505 may have a shape tailored to create a specifically shapedmagnetic field. In some aspects the ferromagnetic element 5505 may alsobe fashioned to provide a specific sensitivity to distance variationsbetween the sensor system 5500 and the ferromagnetic target 5555.

Magnetic sensors 5515,5520,5525,5530 may operate to sense the fluxdensity and may be located in an orbital configuration at a constantradial distance from the axis of symmetry of the ferromagnetic element5505. The magnetic sensors may also be positioned such that theiroutputs are approximately the same. While four magnetic sensors areshown, it should be understood that any suitable number of magneticsensors may be utilized. Outputs of the magnetic sensors 5515, 5520,5525, 5530 may be provided to any suitable conditioning circuitry 5535.Conditioning circuitry 5535 may include signal processing circuitry forprocessing the sensor outputs, for example, to provide compensation,filtering, noise reduction, or any other suitable signal processing. Thesensor output signals may generally be processed to provide a sensorsystem output 5550. The use of additional sensors may improve the noiseimmunity of the system. The ferromagnetic element 5505 may also operateas a magnetic isolation cage for the magnetic sensors minimizingexternal magnetic interference from the surrounding environment. Thesensor system 5500 is thus configured to measure alterations in themagnetic flux density vector detected by the magnetic sensors. In oneaspect, the sensor system 5500 may measure alterations in the magneticflux density vector due to the presence of the ferromagnetic target5555.

FIG. 11 shows an exemplary arrangement of magnetic sensors around theferromagnetic element. In this aspect magnetic sensors may be arrangedin pairs 5610 and 5615, 5620 and 5625, 5630 and 5635, 5640 and 5645 withalternating orientations relative to the flux density lines between theferromagnetic element 5505 and the magnetic source 5510. In this aspect,each sensor pair may provide a differential output. Summing 5650 anddifferential conditioning 5655 circuitry may be part of conditioningcircuitry 5535 and may further provide sensor system output 5550 as adifferential signal. The use of differential outputs may improve noiseimmunity, in particular where signals have low levels, are subject to ahostile electrical electromagnetic environment, or travel anyappreciable distance. For example, providing sensor system output 5550as a differential signal may improve noise immunity as the output isprovided to reading device 5660.

In other aspects, the magnetic sensors do not have to be placed at equalradial distance from the axis of symmetry and that their outputs neednot be necessarily equal and yet the outputs can be suitably processedto yield the effective target distance. It should be understood that anynumber of magnetic sensors may be used, either ungrouped, or groupedtogether in any suitable number or arrangement.

Returning to FIG. 10 , the ferromagnetic target 5555, once located infront of the sensor system 5500 alters the magnetic flux density vectordetected by magnetic sensors 5515, 5520, 5525, 5530, thus affectingoutput signal 5550. The distance 5560 between the target 5555 and thesensor system may determine the value of sensor system output 5550. Thesensor system output 1550 may vary according to any magnetic fluxvariations introduced by one or more scales that may be attached to orintegral with ferromagnetic target 5555.

The shape of the magnetic source 5510 and the ferromagnetic element 5505may be modified to obtain a particular flux density pattern orconfiguration, or to optimize or otherwise improve the sensor systemoutput 5550 or the distance 5560. For example, in some embodiments, atleast one of the ferromagnetic element 5505 and the magnetic source 1510may have the shape of a cylinder, cone, cube or other polyhedron,paraboloid, or any other suitable shape. As mentioned above, any numberof sensors may be utilized. Furthermore, the sensors may have anysuitable arrangement for obtaining a particular flux density pattern, orfor optimizing the sensor system output 1550 or the distance 1560.

The sensor system 5500 is suitable for use in the aspects of thedisclosed embodiment described herein, for example, through a wall ofnon-magnetic material that may isolate a target rotor or scale from thesensor system. The sensor system 5500 is suitable for use in vacuumautomation system embodiments. The sensor system 5500 is particularlysuited for measuring magnetic flux, gaps and scales for all of theaspects of the disclosed embodiment described herein.

Referring again to FIGS. 3 and 4A-4D, as may be realized, in one aspectthe transfer apparatus 800 may include a Z-drive 800Z for moving therobot arm linearly along a central axis of rotation X of the arm. Abellows or other suitable seal 1699 may be provided for accommodatingrelative axial movement (e.g. vertical, Z-axis) between the at least onearm link and frame wherein the seal is located on one side of the armand the drive motors 1602A, 1602B (e.g. drive section) are located onthe opposite side of the arm. As may be realized this arrangement allowsthe length of the stationary post 1610 to be independent or decoupledfrom the length of the z-stroke provided by the Z-axis drive.

Referring to FIGS. 4C and 4D, sealing of the drive section within thearm 810 will be described. As can be seen, the stators 1603A, 1603B maybe isolated from the vacuum environment in which the robot arm operatesin any suitable manner. In one aspect, isolation may be done by the useof any suitable barrier, for example barrier 612. In other aspects, anysuitable means of isolating the stators 1603A, 1603B may be used.Magnets 1604M of the rotors 1604A, 1604B may also be isolated from thevacuum in any suitable manner. In one aspect, magnetic isolation may beachieved with, e.g., a ferrofluidic seal 1670. In other aspects, anysuitable means of magnet isolation may be used to isolate the rotormagnets from the vacuum environment in which the robot arm operates. Inyet alternate embodiments, variable reluctance motors may be used toremove the need for the magnet. FIG. 4D is an exemplary illustration ofseal SL locations for sealing the vacuum environment in which the robotarm operates.

It is noted that the drive motors of disclosed herein may be applied toany suitable drive system such as, for example, those disclosed in U.S.patent application Ser. No. 12/175,278 filed on Jul. 7, 2008; Ser. No.13/270,844 filed on Oct. 11, 2011; and Ser. No. 13/270,844 filed on Oct.11, 2011 the disclosures of which are incorporated by reference hereinin their entireties.

Referring now to FIGS. 5A and 5B, in another aspect of the disclosedembodiment, a portion of an exemplary transport apparatus 1799 isdisclosed. The exemplary transport apparatus may be substantiallysimilar to the transport apparatus 800 described above in that thetransport apparatus may include, for example, a frame, at least one ormore shaftless drive sections, Z-motors allowing for motion along theZ-axis, and at least one or more robot arms. The at least one or moredrive sections may be mounted to the frame, such as frame 840 at ashoulder axis of rotation X in order to rotate links of a robot arm foreffecting extension/retraction of the arm. The one or more drivesections may further be connected to a Z-motor/drive system to allow formovement of the robot arm along the Z-axis in a direction substantiallyperpendicular to an axis of extension/retraction R (FIG. 3 ) of the arm.The exemplary aspect of the disclosed embodiment shown in FIGS. 5A and5B includes at least two drive sections 1700A and 1700B and having tworobot arms 1720A, 1720B (which may be substantially similar to the robotarm described above with respect to FIG. 3 in that the arm includes anupper arm 810, forearm 820 and at least one end effector 830). In otheraspects the transport apparatus 1799 may include more or less than tworobot arms and two drive sections (e.g. the transport apparatus 1799 hasat least one robot arm and at least one drive section). In one aspectthe drive sections 1700A, 1700B may be disposed or distributed betweenor “layered” with the arms 1720A, 1720B such that one drive section1700A is disposed substantially between the arms 1720A, 1720B while theother drive section 1700B is disposed on an opposite side of an arm suchas below arm 1720B (or above arm 1720A). In another aspect, the drivesections 1700A, 1700B may be disposed at least partially within arespective arm 1720A, 1720B. In still another aspect both drive sections1700A, 1700B may be disposed between the arms 1720A, 1720B such that thedrive sections 1700A, 1700B have a mirrored or inverted configurationrelative to one another (e.g. drive section 1700A is connected to thearm 1720A from the bottom of the arm and drive section 1700B isconnected to arm 1720B from a top of the arm). In other aspects of thedisclosed embodiment, other configurations may be possible—for instanceconfigurations having only one drive section and one robot arm, orconfigurations having more than two drive sections with more than tworobot arms, or in-line configurations having multiple drive sectionsarranged within the same plane within a robot arm, or configurationshaving one or more Z-drives or any combination thereof. In yet otheraspects, any suitable configuration of the transport apparatus may bepossible such that the drive motors of FIGS. 5A and 5B are incorporatedinto the transport apparatus configuration.

In this aspect, a post 1701 is fixed to the frame 840. The fixed post1701 may, in one aspect of the disclosed embodiment, be segmented (see1701A in FIG. 5A), e.g. having different sections or portions coupled toeach other. The different portions of the fixed post 1701A may becoupled together in any suitable manner. Any suitable seals may also beprovided between the different portions of the fixed post 1701A, suchas, for example, seals 1710. In other aspects, the fixed post 1701 mayhave a unitary one-piece construction or any other suitableconfiguration. The one or more robot arms 1720A, 1720B may be rotatablymounted to fixed post 1701 in any suitable manner such as describedbelow. Each robot arm 1720A, 1720B may include its own drive sectionthat includes an inner rotor 1705A, 1705B, a stator 1703A, 1703B, and anouter rotor 1704A, 1704B.

The inner rotor 1705A, 1705B may be movably mounted to the fixed post1701 in any suitable manner so that the inner rotor 1705A, 1705B may befree to rotate about the fixed post 1701. The inner rotor 1705A, 1705Bmay be supported on the fixed post 1701 in any suitable manner, such asby, for instance, bearings 1702A, 1702B. In other aspects of thedisclosed embodiment, bearings may be disposed in any other suitablelocations other than that shown in FIGS. 5A and 5B to support the innerrotor 1705A, 1705B. The inner rotors 1705A, 1705B may be nested withinthe stator 1703A, 1703B, such that the stator 1703A, 1703B surrounds orcircumscribes a periphery of the inner rotor 1705A, 1705B (e.g. isconcentric with the inner rotor 1705A, 1705B) and lies in the same planeso that the inner rotors 1705A, 1705B may rotate freely about the fixedpost 1701. The inner rotor 1705A, 1705B may be configured to interfacewith the stator and include, for example, suitable interfacingcomponents 1705A′, 1705B′ such as magnets configured to effect theinterface between the inner rotor and the stator.

Referring still to FIGS. 5A and 5B, the stator 1703A, 1703B may also beconnected to the fixed post 1701 to be rotationally stationary relativeto the fixed post 1701. In one aspect of the disclosed embodiment, thestator 1703A, 1703B may be connected in any suitable manner to the fixedpost 1701 or frame 840 (FIG. 3 ) so that the stator 1703A, 1703B isrotationally stationary with respect to the fixed post 1701. Each of thestators 1703A, 1703B may be a segmented stator, for example, the stators1703A, 1703B may be segmented so as to include two individually operablesets of windings. One segment, for instance, segment A of stators 1703A,1703B may be configured to drive the inner rotors 1705A, 1705B. Theother segment, for instance, segment B of stators 1703A, 1703B may beconfigured to drive the outer rotors 1704A, 1704B. Each segment A, B maybe suitably sized to provide a desired torque for rotating therespective arm link. For example, stator segment A may be larger thanstator segment B to provide sufficient torque for rotating the innerrotor 1705A, 1705B which may have a smaller diameter than the outerrotor 1704A, 1704B (e.g. the portion of the inner rotor interfacing withthe stator may be of a smaller diameter than the portion of the outerrotor interfacing with the stator). In other aspects, segment B may belarger than segment A or segments A and B may be substantially the samesize. It is also noted that in one aspect, the winding segments A, B maybe formed by nesting two sets of coils within one another. In otheraspects, the coils for the inner and outer windings may be nested toeach other as two parts. Each segment A, B of stators 1703A, 1703B maybe controlled by a controller, such as controller 170, 400 configuredfor individually energizing each segment A, B, so that each segment A,B, of stators 1703A, 1703B may drive their corresponding inner and outerrotors (1705A, 1705B and 1704A, 1704B, respectively) independently ofeach other. In other aspects, segments A, B of stators 1703A, 1703B maybe controlled by any suitable controller or controllers so that thecorresponding inner and outer rotor may be driven in unison or otherwisetogether. In yet another aspect of the disclosed embodiment, the stators1703A and 1703B may be composed of two separate stators (correspondingsubstantially to segments A and B) wherein one stator (e.g., an innerstator) may be arranged to be nested inside the other stator (e.g., anouter stator) so that the outer stator substantially surrounds theperiphery of the inner stator.

In one aspect of the disclosed embodiment, the outer rotor 1704A, 1704Bmay extend around and substantially surround the fixed post 1701 andsubstantially surround the periphery of the stator 1703A, 1703B so thatthe stator 1703A, 1703B may substantially be nested within the outerrotor 1704A, 1704B. The outer rotor 1704A, 1704B is further arranged sothat it freely rotates about the stationary stator 1703A, 1703B. Theouter rotor 1704A, 1704B may be supported on fixed post 1701 in anysuitable manner such as by, for instance, bearings 1702C, 1702D so as tobe freely rotatable independent of the fixed post 1701. In alternateaspects, the outer rotor 1704A, 1704B have any suitable configurationand be mounted to any suitable structure of the transport apparatus 1799so as to be freely rotatable relative to the fixed post and/or stator1703A, 1703B. The outer rotor 1704A, 1704B may be configured tointerface with the stator and include, for example, suitable interfacecomponents 1704A′, 1704B′ such as magnets configured to effect theinterface between the outer rotor and the stator.

It is noted that in one aspect of the disclosed embodiment, the rotorsdescribed herein may use permanent magnets, but in other aspects, asnoted above, the rotors may also be configured as a reluctance stylerotor or any other suitable rotor type. Other examples of a drivesection having nested rotors and stators are described in U.S. Pat. No.7,891,935 and U.S. application Ser. No. 13/030,856 filed Feb. 18, 2011,the disclosures of which are incorporated by reference herein in theirentireties.

Referring still to FIGS. 5A and 5B, the two drive sections 1700A and1700B are arranged in a stacked configuration such that a drive sectionis disposed at the shoulder of each respective arm about the shoulderaxis X. As noted above, drive sections 1700A, 1700B and arms 1720A,1720B may be configured to have any suitable number of degrees offreedom and any suitable configuration. In one aspect the two drivesections 1700A and 1700B and arms 1720A, 1720B may be substantiallysimilar to each other and as such the drive sections 1700A, 1700B willbe described with respect to drive section 1700A of arm 1720A. In oneaspect the inner rotor 1705A may be connected, for instance, to a pulley1707A in any suitable manner so that as the inner rotor 1705A rotates,the pulley 1707A rotates with the inner rotor 1705A. The pulley 1707Amay be integral to the inner rotor 1705A (i.e. of one-piece constructionwith the rotor) or may be coupled to the inner rotor 1705A in anysuitable manner. As pulley 1707A rotates, the pulley 1707A may, throughany suitable transmission member 1709A, turn another pulley 1712Adisposed about the elbow axis EX in the elbow of the robot arm forrotating the forearm 820 (FIG. 3 ) relative to the upper arm 810. Theouter rotor 1704A may, in turn, be connected to the upper arm in anysuitable manner. In one aspect of the disclosed embodiments, the outerrotor 1704A may be directly coupled to the upper arm so that as theouter rotor 1704A rotates, the upper arm will rotate with the outerrotor 1704A. In alternate aspects, the outer rotor 1704A may beconnected to the upper arm through an arm interface (not shown) so thatas the outer rotor 1704A rotates, the upper arm will rotate with theouter rotor 1704A via the arm interface. As noted above, because drivesections 1700A and 1700B are substantially similar, this configurationmay also be used for drive section 1700B (see e.g. inner rotor pulley1707B, transmission 1709B and elbow pulley 1712B and outer rotor 1704Bmay be connected to the upper arm 810 of arm 1720B for rotating theupper arm). In alternate aspects, any other suitable configuration maybe used.

Referring still to FIGS. 5A and 5B, the drive sections 1700A and 1700Bmay include any suitable sensors for tracking the rotation of the drivesections in a manner substantially similar to that described above. Forexample, referring to drive section 1700A (drive section 1700B may besimilarly configured), an encoder 1741A (see also encoder 1741B fordrive section 1700B) may be disposed for the tracking rotation of theinner rotor 1705A (or rotor 1705B in the case of drive section 1700B),while a second encoder 1740A (see also encoder 1740B for drive section1700B) may be configured for tracking the rotation of the outer rotor1704A (or rotor 1704B in the case of drive section 1700B). The encoders1740A and 1741 may be substantially similar to the previously describedencoders 1640A, 1640B. The encoders may be disposed in any suitableposition or location within the transport apparatus to enable thetracking of rotation and may be configured to use any scale including,but not limited to absolute scales, incremental scales or any othersuitable scale.

The drive sections 1700A and 1700B may also be configured to includeatmospheric/vacuum sealing. For instance, stator 1703A, 1703B may beisolated from the vacuum environment in which the robot arm may operatein any suitable manner. For instance, isolation may be done by anysuitable barrier, such as, for instance, barriers 1711A, 1711B. In oneaspect of the disclosed embodiment, the magnet 1705A′, 1705B′ of aninner rotor 1705A, 1705B may also be isolated from the vacuumenvironment in any suitable manner, such as that described above. Inanother aspect, of the disclosed embodiment, the magnet 1704A′, 1705B′of outer rotor 1704A, 1704B may also be isolated from the vacuumenvironment in any suitable manner, such as that described above. Forexample, one such means of isolating the magnets 1705A′, 1705B′, 1704A′and 1704B′ may be a ferrofluidic seal S1, S2, S3 and S4 similar to theseals described above. In yet another aspect of the disclosedembodiment, the drive sections disclosed may also use variablereluctance motors to remove the need for magnets.

In the aspect of the disclosed embodiment shown in FIGS. 5A and 5B, onlytwo degrees of freedom were disclosed within the drive section. However,in other aspects of the disclosed embodiment, it is possible to increasethe numbers of degrees of freedom within the drive sections by havingadditional stators and rotors (not shown) disposed between the inner andouter rotors so that the additional stators and rotors will increase thenumber of degrees of freedom that can be utilized by the robot arms. Anysuitable number of stators and rotors may be concentrically arranged andnested in a manner substantially similar to that described above.

Referring now to FIG. 6 , a portion of dual arm transport apparatus isshown in accordance with aspects of the disclosed embodiment. It isnoted that the connections between the drive motors and the arms (e.g.the manner in which the arms are driven) may be any suitable connectionssuch as those described in U.S. Pat. Nos. 5,720,590; 5,899,658 and5,813,823 the disclosures of which are incorporated by reference hereinin their entireties. In FIG. 6 a vertically opposed SCARA armconfiguration is illustrated (the forearm and end effectors are notshown as dashed blocks 600, 601 for clarity) such as described in U.S.patent application Ser. No. 13/293,717 filed on Nov. 10, 2011 and Ser.No. 13/417,837 filed on Mar. 12, 2012 the disclosures of which areincorporated by reference herein in their entireties. Here each of thearms 2000, 2001 may be substantially similar to that described abovewith respect to FIG. 3 and includes a drive section 2000D, 2001D (eachhaving e.g. two motors but in other aspects may include more or lessthan two motors) substantially similar to that described above withrespect to any one or more of FIGS. 4A-5B. For example, in one aspectboth drive sections 2000D, 2001D may have a common drive configuration(e.g. both drive sections are configured in the manner described abovewith respect to FIGS. 4A-4D or both drive sections are configured in themanner described above with respect to FIGS. 5A-5B). In another aspectthe drive sections 2000D, 2001D may have different configurations (e.g.one drive section may be configured in the manner described above withrespect to FIGS. 4A-4D while the other drive section is configured inthe manner described above with respect to FIGS. 5A-5B).

FIG. 7 illustrates another dual SCARA arm configuration where each arm2010, 2011 (each of which may be substantially similar to that describedabove with respect to FIG. 3 ) includes a drive section 2010D, 2011D(each having e.g. two motors but in other aspects may include more orless than two motors) substantially similar to that described above withrespect to any one or more of FIGS. 4A-5B. In this aspect the arms 2010,2011 are configured such that the forearms and end effectors(illustrated by dashed boxes 600, 601 for clarity) of each arm 2010,2011 are located on, e.g. a top of the upper arm but in other aspectsthe forearm and end effectors may be located on a bottom of therespective upper arms.

Referring to FIGS. 8 and 9 a portion of a transport robot arm having adual arm configuration is shown in accordance with aspects of thedisclosed embodiment. Each arm 2020, 2021 may be substantially similarto that described above with respect to FIG. 3 and includes two drivemotors substantially similar to those described above except in thisaspect the motors are not vertically stacked one above the other butrather are disposed in the same horizontal plane within a respective oneof the arm links. FIG. 9 illustrates a single arm 2030 configurationsubstantially similar to that shown in FIG. 8 ; e.g. in FIG. 8 the twoarms 2020, 2021 are each mounted to a common shaft 1801 so as to berotatable about the shoulder axis X whereas in FIG. 9 only a single arm2030 is mounted to the shaft 1801, otherwise the drive motorconfiguration for the arms 2020, 2021 and 2030 are substantially thesame. For exemplary purposes, the drive motors of the arms 2020, 2021,2030 will be described with respect to the arm 2030. In this aspect,each drive motor 2030A, 2030B include a stator 2030SA, 2030SB and arotor 2030RA, 2030RB substantially similar to those described above. Itis noted that in one aspect the drive motors 2030A, 2030B may bevariable reluctance motors so that there are no magnets exposed to, forexample, a vacuum environment in which the transport robot operates,otherwise any suitable seals may be provided to isolate the magneticcomponents of the rotors and/or stators in any suitable manner. Thestator 2030SA for drive motor 2030A may be fixed to the shaft 1801 sothat it remains rotationally stationary with respect to, for example,the upper arm 810. The rotor 2030RA may be mounted within and fixed tothe upper arm 810 in any suitable manner so that the upper arm 810 andthe rotor 2030RA rotate as a unit (e.g. when the stator 2030SA drivesthe rotor 2030RA for rotation about the shoulder axis X the upper arm810 rotates with the rotor 2030RA). The stator 2030SB for drive motor2030B may be fixedly mounted to a shaft 1900 disposed within the upperarm 810 so that the stator 2030SA is rotationally fixed with respect tothe shaft 1900. The rotor 2030RB may be mounted in any suitable mannerwithin the upper arm 810 so as to be rotatable about the stator 2030SB.The rotor 2030RB may include an integral pulley (or in other aspects thepulley may be attached to the rotor in any suitable manner) thatconnects the rotor 2030RB, through any suitable transmission to elbowpulley 1620 for drivingly rotating the forearm 820 (FIG. 3 ) in a mannersubstantially similar to that described above. For example, the elbowpulley may be fixedly attached to the forearm 820 in any suitable mannerso that when the elbow pulley 1620 rotates the forearm 820 rotates withit. In other aspects, the rotor 2030RB may drive rotation of the elbowpulley 1620 in nay suitable manner. In still other aspects of thedisclosed embodiments, any suitable robot arm configuration may be used.Suitable examples of robot arms with which the drive system of theexemplary embodiments may be employed can be found in U.S. patentapplication Ser. No. 13/270,844 filed on Oct. 11, 2011 and Ser. No.13/270,844 filed on Oct. 11, 2011 the disclosures of which areincorporated by reference herein in their entireties.

In accordance with one or more aspects of the disclosed embodiment ofthe disclosed embodiments a substrate transport apparatus is provided.The substrate transport apparatus includes a frame, at least one armlink rotatably connected to the frame and a shaftless drive section. Theshaftless drive section including stacked drive motors for rotating theat least one arm link relative to the frame through a shaftlessinterface, each of the stacked drive motors including a stator havingstator coils disposed on a fixed post fixed relative to the frame and arotor substantially peripherally surrounding the stator such that therotor is connected to a respective one of the at least one arm links forrotating the one of the at least one arm link relative to the framecausing an extension or retraction of the one of the at least one armlink, where the stacked drive motors are disposed in the at least onearm link so that at least part of each stator is within a common armlink of the at least one arm link.

In accordance with one or more aspects of the disclosed embodiment, theshaftless drive section is disposed substantially within the at leastone arm link.

In accordance with one or more aspects of the disclosed embodiment, thestator coil is isolated from vacuum.

In accordance with one or more aspects of the disclosed embodiment, thesubstrate transport apparatus further includes a second drive sectiondisposed at least partially within the frame and configured to linearlymove the at least one arm link in a direction substantially normal (e.g.vertical, Z-axis) to a plane containing a direction of extension orretraction of the at least one arm link. Further, the at least one armlink is connected to the frame by a seal capable of accommodatingrelative axial movement (e.g. vertical, Z-axis) between the at least onearm link and frame wherein the seal is located on one side of the armand the first drive section is located on the opposite side of the arm.

In accordance with one or more aspects of the disclosed embodiment, theat least one arm link includes an upper arm rotatably connected to theframe about a shoulder axis of rotation, a forearm rotatably connectedto the upper arm about an elbow axis of rotation and at least onesubstrate holder rotatably connected to the forearm about a wrist axisof rotation and the at least one drive motor includes at least twostacked drive motors where each motor drives rotation of a respectiveone of the upper arm and forearm.

In accordance with one or more aspects of the disclosed embodiment, theat least one arm link includes an upper arm rotatably connected to theframe about a shoulder axis of rotation, a forearm rotatably connectedto the upper arm about an elbow axis of rotation and at least onesubstrate holder rotatably connected to the forearm about a wrist axisof rotation and the at least one drive motor includes at least threestacked drive motors where each motor drives rotation of a respectiveone of the upper arm, forearm and at least one substrate holder.

In accordance with one or more aspects of the disclosed embodiment, theat least one arm link includes an upper arm rotatably connected to theframe about a shoulder axis of rotation and at least one substrateholder movably mounted to the upper arm for linear travel along at leasta portion of a length of the upper arm and the at least one drive motorincludes at least two stacked drive motors where one of the at least twostacked drive motors drives rotation of the upper arm and the other onesof the at least two stacked drive motors drives the linear travel of arespective one of the at least one substrate holder.

In accordance with one or more aspects of the disclosed embodiment, theshaftless drive section includes seals for sealing the stator from anenvironment in which the at least one arm link operates. Further, eachrotor includes magnets for interfacing with a respective stator whereinthe drive section includes seals for sealing the magnets of the rotorfrom an environment in which the at least one arm link operates.

In accordance with one or more aspects of the disclosed embodiment, aheight of the shaftless drive section is decoupled from a Z-travel ofthe substrate transport apparatus.

In accordance with one or more aspects of the disclosed embodiment asubstrate transport apparatus is provided. The substrate transportapparatus includes a frame, at least one arm link rotatably connected tothe frame and a shaftless distributed drive section disposedsubstantially within the at least one arm link. The shaftlessdistributed drive section including at least two drive motors where oneof the at least two drive motors is connected to the at least one armlink for rotating the at least one arm link relative to the frame, andthe at least two drive motors are arranged within the at least one armlink side by side along a common horizontal plane.

In accordance with one or more aspects of the disclosed embodiment, eachof the at least two drive motors includes a stator and a rotorsubstantially peripherally surrounding the stator.

In accordance with one or more aspects of the disclosed embodiment, thesubstrate transport apparatus further includes a second drive sectiondisposed at least partially within the frame and configured to linearlymove the at least one arm link in a direction substantiallyperpendicular to a direction of extension or retraction of the at leastone arm link.

In accordance with one or more aspects of the disclosed embodiment asubstrate transport apparatus is provided. The substrate transportapparatus includes a frame, at least one arm rotatably connected to theframe and having at least an upper arm and forearm. The substratetransport apparatus also includes a shaftless drive section connected tothe frame. The shaftless drive section including at least one drivemotor including a stator having at least two nested stator coils, aninner rotor substantially peripherally surrounded by the stator and anouter rotor substantially peripherally surrounding the stator such thatthe inner rotor is connected to the forearm for rotating the forearm andthe outer rotor is connected to the upper arm for rotating the upperarm.

In accordance with one or more aspects of the disclosed embodiment thesubstrate transport apparatus includes a second drive section disposedat least partially within the frame and configured to linearly move theat least one arm link in a direction substantially normal to a planecontaining a direction of extension or retraction of the at least onearm link.

It should be understood that the foregoing description is onlyillustrative of the aspects of the disclosed embodiment. Variousalternatives and modifications can be devised by those skilled in theart without departing from the aspects of the disclosed embodiment.Accordingly, the aspects of the disclosed embodiment are intended toembrace all such alternatives, modifications and variances that fallwithin the scope of the appended claims. Further, the mere fact thatdifferent features are recited in mutually different dependent orindependent claims does not indicate that a combination of thesefeatures cannot be advantageously used, such a combination remainingwithin the scope of the aspects of the invention.

What is claimed is:
 1. A sealed actuator comprising: stacked motormodules, each motor module having: a motor module housing, a motorstator attached to a respective motor module housing, a motor rotor incommunication with a respective motor stator, and a stator seal disposedbetween the motor stator and motor rotor, surrounding the motor rotorand having a sealing surface interface, that interfaces with arespective sealing housing surface of the motor module housing, facingthe motor rotor to seal the motor stator from the motor rotor; where themotor module housings are stacked against each other and the sealinghousing surface interfaced, at the sealing surface interface facing therotors, to the respective stacked stator seals of the motor modulehousings forms a substantially continuous seal interface of the stackedmotor modules sealed by the stacked stator seals to form a continuousbarrier seal between the motor rotors and the motor stators.
 2. Thesealed actuator of claim 1, wherein the motor stator of each motormodule is isolated from vacuum.
 3. The sealed actuator of claim 1,further comprising an encoder interfacing with each of the stacked motormodules, the encoder including a sensor system and at least one scale,the sensor system being mounted to the motor module housing and thescale is integrated into the motor rotor of a respective one of thestacked motor modules such that an interface plane between the sensorsystem and the scale is arranged at an angle relative to an interfaceplane between the motor stator and the motor rotor of the respectivestacked motor module.
 4. The sealed actuator of claim 1, wherein: themotor stator comprises two stator winding segments; and the motor rotorincludes an inner rotor that is circumscribed by the motor stator and anouter rotor that circumscribes the motor stator; wherein, the two statorsegments are configured so each of the two stator winding segmentsdrives a respective one of the inner rotor and outer rotor independentlyof each other.
 5. The sealed actuator of claim 4, wherein the two statorwinding segments include two sets of nested coils.
 6. The sealedactuator of claim 1, wherein the stacked motor modules are configuredfor placement in a joint of a substrate transport apparatus arm so as tobe at least partially within at least one arm link of the substratetransport apparatus arm.
 7. The sealed actuator of claim 6, wherein oneof the stacked motor modules is configured to couple with the at leastone arm link for substantially directly driving rotation of the at leastone arm link and another of the stacked motor modules is configured todrive a transmission within the at least one arm link.
 8. The sealedactuator of claim 7, where: the at least one arm link is an upper arm ofthe substrate transport apparatus arm and the one of the stacked motormodules is configured to drive rotation of the upper arm; and thetransmission drives a forearm of the substrate transport apparatus armand the another of the stacked motor modules is configured to driverotation of the forearm through the transmission.
 9. A sealed actuatorcomprising: drive motors arrayed in column, each drive motor having: amotor housing, a motor stator attached to a respective motor housing, amotor rotor in communication with a respective motor stator, and astator seal disposed between the motor stator and motor rotor,surrounding the motor rotor and having a sealing surface interface, thatinterfaces with a respective sealing housing surface of the motorhousing, facing the motor rotor to seal the motor stator from the motorrotor; where the drive motors arrayed in column are arrayed at differentheights with respect to each other and the sealing housing surfaceinterfaced, at the sealing surface interface facing the rotors, to therespective stator seals of the motor housings forms a substantiallycontinuous seal interface of the drive motors arrayed in column sealedby the stator seals to form a continuous barrier seal between the motorrotors and the motor stators.
 10. The sealed actuator of claim 9,wherein the motor stator of each drive motor is isolated from vacuum.11. The sealed actuator of claim 9, further comprising an encoderinterfacing with each of the drive motors arrayed in column, the encoderincluding a sensor system and at least one scale, the sensor systembeing mounted to the motor housing and the scale is integrated into themotor rotor of a respective one of the drive motors arrayed in columnsuch that an interface plane between the sensor system and the scale isarranged at an angle relative to an interface plane between the motorstator and the motor rotor of the respective drive motor arrayed incolumn.
 12. The sealed actuator of claim 9, wherein: the motor statorcomprises two stator winding segments; and the motor rotor includes aninner rotor that is circumscribed by the motor stator and an outer rotorthat circumscribes the motor stator; wherein, the two stator segmentsare configured so each of the two stator winding segments drives arespective one of the inner rotor and outer rotor independently of eachother.
 13. The sealed actuator of claim 12, wherein the two statorwinding segments include two sets of nested coils.
 14. The sealedactuator of claim 9, wherein the drive motors arrayed in column areconfigured for placement in a joint of a substrate transport apparatusarm so as to be at least partially within at least one arm link of thesubstrate transport apparatus arm.
 15. The sealed actuator of claim 14,wherein one of the drive motors arrayed in column is configured tocouple with the at least one arm link for substantially directly drivingrotation of the at least one arm link and another of the drive motorsarrayed in column is configured to drive a transmission within the atleast one arm link.
 16. The sealed actuator of claim 15, where: the atleast one arm link is an upper arm of the substrate transport apparatusarm and the one of the stacked motor modules is configured to driverotation of the upper arm; and the transmission drives a forearm of thesubstrate transport apparatus arm and the another of the stacked motormodules is configured to drive rotation of the forearm through thetransmission.